This invention relates generally to the field of antennas. More specifically, an antenna is provided that is particularly well-suited for use in wireless mobile communication devices, generally referred to herein as xe2x80x9cmobile devicesxe2x80x9d, such as Personal Digital Assistants, cellular telephones, and wireless two-way email communication devices.
Many different types of antenna for mobile devices are known, including helix, xe2x80x9cinverted Fxe2x80x9d, folded dipole, and retractable antenna structures. Helix and retractable antenna are typically installed outside of a mobile device, and inverted F and folded dipole antennas are typically embedded inside of a mobile device case or housing. Generally, embedded antennas are preferred over external antennas for mobile devices for mechanical and ergonomic reasons. Embedded antennas are protected by the mobile device case or housing and therefore tend to be more durable than external antennas. Although external antennas may physically interfere with the surroundings of a mobile device and make a mobile device difficult to use, particularly in limited-space environments, embedded antennas present fewer such challenges. However, established standards and limitations on near-field radiation tend to be more difficult to satisfy for embedded antennas without significantly degrading antenna performance.
According to an aspect of the invention, an antenna comprises a first conductor section electrically coupled to a first feeding point, a second conductor section electrically coupled to a second feeding point, and a near-field radiation control structure adapted to control characteristics of near-field radiation generated by the antenna.
In accordance with another aspect of the invention, a wireless mobile communication device comprises a receiver configured to receive communication signals, a transmitter configured to transmit communication signals, and an antenna having a first feeding point and a second feeding point connected to the receiver and the transmitter. The antenna comprises a first conductor section connected to the first feeding point, a parasitic element positioned adjacent the first conductor section and configured to control characteristics of near-field radiation generated by the first conductor section, and a second conductor section connected to the second feeding point and comprising a diffuser configured to diffuse near-field radiation into a plurality of directions.
Further features and aspects of the invention will be described or will become apparent in the course of the following detailed description.